This invention relates to the field of electrical power supplies and, more particularly, power supplies which provide conditioned AC output voltage power, such as those which may be employed in providing power for the operation of computing or telecommunications systems.
Electrical power is used to drive the operation of various mechanical, electromechanical, electronic and other devices. One form of electrical power is alternating current (AC), as provided by public utility companies. Typical AC voltages provided (e.g., a standard wall outlet in the home) are in sine wave form, can have voltage ranges from 90 to 132 AC volts and can have various forms of electrical "noise" superimposed on the AC voltage wave provided. Typical AC voltages can be provided in single or multiple voltage "phases" (e.g., a three-phase system).
Certain electrical and electronic devices utilizing AC power need such power having specifically defined ("conditioned") parameters of voltages, currents and waveforms to drive precision components, such as those used in computer systems. In addition, various electronic devices and computer systems in particular, also rely on the continuous supply of power to effectively operate.
Various techniques have been developed to provide power to computer systems. Transverter devices in various forms convert AC to DC and vice versa. Several such transverter approaches are described in copending application Ser. No. 08/164,649 filed on Dec. 8, 1993 by Gerald J. Brand et al, entitled INPUT POWER PROCESSING POWER ARCHITECTURE, which is a File Wrapper Continuation of application Ser. No. 07/896,260 filed on Jun. 10, 1992. These applications and the technology described therein are incorporated herein by reference.
Various techniques have also been developed to provide a continuous or uninterruptable supply of power to computer systems. DC battery backup units are well known for providing auxiliary power to a computer system in the event of an outage of AC power supplied by the utility company.
However, not only does a need exist for the continuous supply of power, but there is also a need for the continuous supply of conditioned AC power.
Various prior approaches have been employed to provide continuous supply of conditioned AC power, but they have disadvantages. For example, one approach uses backup AC power supplies which are switched into place when the primary supplies becomes defective. While such a procedure attempts to address the continuity of AC power, this approach is inefficient. Typically, these backup AC power supplies are not utilized until they are needed to be switched into place. The switching is typically manual and can also cause brief discontinuities while the switching is being undertaken. What is needed is a effective, easy to use and implement approach for providing conditioned AC power, and for providing of conditioned AC power on a continuous basis. The invention as described herein provides such an approach.